The late Morris (Tiny) Weintraub, one of the founders of this magazine, used to say that "The operator is his own worst enemy." With the passage of time, we have come to recognize that this principle is not confined to operators. At one time or another, most of us are our own worst enemies, and so are most industries.

But, as we've noted before, operators do have a tendency to take criticism to heart. This is one of our industry's great strengths -- we wish the airline business were as receptive -- but it can have a depressing effect.

Many years ago, in the heyday of the Coffee Development Group, its vending taskforce held a meeting in Washington, DC. At the welcome reception on the evening before the formal program, operators were invited to take part in a taste-test. Each participant sampled three coffees, identified as "restaurant," "home" and "vended," and to rate them. Only one rated the "vended" brew highest. (He told us, "They all tasted alike, and I'm in the vending business, so I preferred the vended one.") In fact, they were all alike; they all had been prepared by a single-cup fresh-brew vending machine. The point, hammered home the next morning, was that operators will have a difficult time selling a product in which they themselves do not believe.

This is worth keeping in mind nowadays, regarding the sale of snack foods. Continual depiction of vending machines as monsters compelling victims to consume "junk food" may be demoralizing.

But it need not be. Even if we suppose, with many current alarmists, that "healthy" is more or less the same thing as "not being fat," it turns out that some of the assumptions underlying the assault on popular foodstuffs are, at the least, oversimplified.

Several news stories published late last year demonstrated that the classic view of body weight maintenance has not been invalidated. One that received considerable coverage was a 10-week experiment by Mark D. Haub, Ph.D., associate professor in the Department of Human Nutrition at Kansas State University. During that period, he made snack foods two-thirds of his daily food intake. The news accounts emphasize Twinkies, but he varied those with other snack cakes, cookies and sugary cereals, as well as chips.

As CNN reported the story on December 14, 2009, Dr. Haub did this to demonstrate that "in weight loss, pure calorie counting is what matters most -- not the nutritional value of the food." We are glad to note that CNN referred to the experiment as involving a "convenience store diet." The key is that he limited himself to less than 1,800 calories per day, rather than the approximately 2,600 calories that an adult male of his pre-diet weight typically consumes. At the conclusion of the experiment, Dr. Haub had lost 27 lbs., and his "body mass index" had gone from 28.8 (regarded as "overweight") to 24.9, normal for a man of his size. His "bad" cholesterol (LDL) level declined 20% and his "good" (HDL) cholesterol level increased by the same percentage; his triglyceride level also improved.

Dr. Haub pointed out that it is worth asking whether he was "healthier" after the test than he had been before it, or whether, in current discussions of health from a biological standpoint, "we're missing something?" The story may be found online at cnn.com.

That question also is raised by another recent report, this one detailing a study published in the Annals of Internal Medicine (Dec. 21, 2010). It suggests that a fatty acid found in whole-fat dairy products may lower the risk of type 2 diabetes. The study is indexed on the Annals' website, annals.org.

The news report, by HealthDay, quotes study author Dr. Dariush Mozaffarian of Brigham and Women's Hospital and the Harvard School of Public Health as warning against jumping to conclusions. "This study confirms that something about dairy is linked very strongly to a lower risk of diabetes, but no single study should be enough to change guidelines."

This is eminently sensible, but we think it raises the further question of whether the guidelines command sufficient confidence to be hardened into mandates and prohibitions. An underlying principle of science is that one never comes up with a final answer; there is always more to discover, and it is important to keep an open mind and remain receptive to new evidence that appears to contradict previous conclusions.

That principle, of course, runs at cross-purposes to the demand for definitive answers right now. We think it is important to keep this in mind. Even if it is not practical to stand athwart a current popular mania and shout "stop," we should continue to argue, quietly, for common sense.

The present assault on snack foods, meat, "sugary" beverages, among many other things, seems to us a manifestation of a fundamentally religious impulse, the latest in a series of periodic outbursts of revulsion against gluttony. As such, it may (or may not) be valuable in redirecting behavior, but it should not be mistaken for a long-deferred recognition of Truth.